Air Traffic Manager, ZID-1 Our office has been asked to provide analysis on the flight path of beacon code target 3743 (AAL77) from September 11, 2001. Specifically, we were asked to analyze any data available from the time of the loss of a transponder response (approximately 12:56:19Z, Point A) and the time that a plausible "primary" radar target was identified (approximately 13:04:32Z, Point B). Although our office holds no certification in analyzing radar data, we periodically compile and analyze this form of data in reviewing HOST/NAS performance. Several of the specialists from this office, contractors and AF personnel conducted a manual analysis and plotting of radar data available. The results from this activity include a depiction of the route of flight that is supported by the data available and is deemed to be most likely by the participants. This attached depiction is a manual reconstruction of this analysis. This reconstruction is an approximation and is not intended to give the exact flight path. At the time the transponder stopped responding, the radar sort box area for the flight was QHY (Higby, WV), which is a "beacon only" site and does not report "primary" radar data. Once the transponder stopped responding, QHY could not provide any radar data on the flight. The secondary source of radar data for this radar sort box area was QRJ (Lynch, KY). QPJ did not provide conclusive primary radar data in ascertaining the aircraft position or flight path. The most useful data used in this activity was derived from data recordings of the QBE (Bedford, VA) radar site. QBE reported a radar reinforced beacon target up until the transponder stopped responding. At the time the transponder stopped responding, QBE reported a primary target that is consistent with the expected radar values and matches the route of flight, which would be expected, given the approximate location of the plausible "primary" radar target observed at Point B. The approximate location of the plausible "primary" radar target is derived from the SATORI analysis and other supporting data, which indicate a "primary" radar target displayed to the Air Traffic Control Specialists at Point B of the depiction. The availability of a "primary" target display to the ATCSs at Point B is likely the result of better data being available from QPJ radar at that point. Between the time of the lost transponder data (Point A) and the time of the "primary" target being displayed (Point B), no radar data was available to the Air Traffic Control Specialists. The reconstruction attached was only possible through the compilation of other radar data sources not ordinarily displayed to the controllers under these circumstances.

If you have any questions regarding this information, please contact me at extension 591.

July 17, 2003 VIA HAND DELIVERY Daniel Marcus General Counsel c/o Dana Hyde, Esquire National Commission on Terrorist Attacks Upon the United States 301 7th Street, SW, Room 5125 Washington, DC 20407 Dear Mr. Marcus: I write in response to the July 2, 2003 request by the National Commission on Terrorist Attacks Upon the United States for production of copies of certain documents by the National Transportation Safety Board ("NTSB"). As you know, the NTSB is an independent establishment of the United States Government, responsible for, among other things, investigating aircraft accidents. See49U.S.C. § 1131(a)(l)(A). The law enforcement investigation of the events of September 11, 2001 was under the jurisdiction of the Federal Bureau of Investigation ("FBI"), but, at FBI's request and under its direction, the NTSB provided technical assistance. The NTSB helped document factual information regarding the aircraft involved in the events of September 1 1th, and delivered this information and numerous reports and other technical products to the FBI. The material collected and produced by NTSB personnel for the FBI is, and was at all times, under the FBI's control. The Commission's electronic request specifically sought, "[a]ll records relating to the NTSB's review of radar data from the United States Air Force and Federal Aviation Administration concerning (1) the hijacked aircraft on September 11, 2001, and (2) the United States Government's air defense response to the hijacked aircraft." The request also specifically "includes, but is not limited to, both the raw radar files and the NTSB's analysis of the combined radar information."1 Subsequently, Christopher Julius, an attorney on my staff, and I have had
1 As you can see from the attached list, NTSB only has material responsive to the first part of your request. I am advised that the NTSB did not conduct any investigation or collect any records (other than those we are providing in response to the first part of the request) that would pertain to the United States Government's air defense response to the hijacked aircraft.

conversations with Commission Deputy General Counsel Steven Dunn and staff counsel Dana Hyde, as well as with Department of Justice liaison counsel Brian Hook, about your request. Today, the FBI authorized NTSB to provide to the Commission copies of all material that NTSB delivered to the FBI. For your convenience, I have attached a list of that material. I am advised that this material is included within the nondisclosure agreement for Moussaoui-related material reached between the Commission and the Executive Branch. With the exception of a copy of the cockpit voice recorder recording ("CVR") and an early copy of a working draft of the CVR transcript from United Airlines Flight 93 CVR, I am herewith providing the Commission with copies of all such material.2 We trust our production, which is both responsive to and extends beyond the boundaries of your written request, will prove helpful to you. If you have any questions, or need assistance with anything, please feel free to call on us. Mr. Julius can provide the best assistance, and he can be reached at (202) 314-6087. Sincerely,

Ronald S. Bartocchi General Counsel Enclosures

2 CVR recordings require different treatment, in part because of the special restrictions against public disclosure imposed by Congress. See49U.S.C.§ 1114(c);seea/so49U.S.C. § 1154(a) (setting forth detailed provisions designed to minimize dissemination of non-public CVR information). I am advised that tiie FBI, however, which is in possession of the original CVR tape and the final draft of the CVR transcript from Flight 93, will respond directly to any Commission request pertaining to the CVR. You will note that some of the products we are delivering to you incorporate information from die FBI transcript of the Flight 93 CVR recording.

Background: AOS-310 has been asked to provide analysis on the flight path of AAL77, and validation of the initial analysis performed by Indianapolis Air Route Traffic Control Center (ZID ARTCC). Refer to the Memorandum titled: Information: AAL77 Flight Path Information, dated September 17, 2001. Conclusions: 1. 2. A beacon target was last displayed at 12:56:19z. A beacon target was last received at 12:56:30z. This target was not displayed due to Radar Sort Box (RSB) assignments. Note: The beacon target received at 12:56:30zfrom the Supplemental Radar was not displayed because a return was expected from the Preferred Radar at 12:56:3 7z. Because no subsequent beacon target was reported, in can be assumed that the transponder was disabled between 12:56:30zandl2:56:37z. 3. The track position presented to the controller beyond 12:56:19z consisted of extrapolated track positions (i.e., 'coasting' track) based upon last known track position and heading. The presentation first indicated lack of Mode 3/a at 12:56:59z (per system requirements), and indicated the track to be in 'coast' status at 12:57:20z (per system requirements). ZID's initial analysis and description of the radar reporting capability is accurate (refer to Memorandum of September 17, 2001). The flight path depiction appears to contain moderate positional inaccuracies; most probably the result of limited time constraints and rudimentary transformation techniques. It should be noted the ZID paper stated the depiction to be an "approximation and is not intended to give the exact flight path".

4.

5. The flight path was re-plotted to reflect the results of the AOS-310 analysis to provide a more accurate depiction of flight position and situation display. The 'first displayed primary' was the first primary target presented for display that fell along the calculated flight path. This target was received from Lynch Radar and presented for display at 13:04:32z. 6. The following diagrams accurately depict the flight path from 12:46:58z through 13:06:30z: a. b. The green path depicts the beacon track as received and presented to the display (12:46:58z through 12:56:19z) The blue path depicts the trail of primary returns (12:56:45z through 13:06:30z). Note that the majority of these returns were not presented for display due to RSB assignments and lack of target reporting by the Preferred and Supplemental Radar. The red path depicts the track display as presented to the controller beyond 12:56:19z Each 'box' represents 256 square nmis.